In temperatures that are expected to climb to more than 40 degrees Celsius, robed pilgrims will slowly circle the Kaaba, Islam’s holiest site, the black cubic structure at the centre of Mecca’s Grand Mosque.
About 1.4 million pilgrims arrived in Saudi Arabia ahead of the multi-day hajj, one of the five pillars of Islam that must be performed at least once by all Muslims with the means.
Authorities have ratcheted up anti-heat measures such as extra shade to avoid a repeat of last year, when 1,301 people died as temperatures hit 51.8C.
On Wednesday, pilgrims will perform the tawaf, walking seven times around the Kaaba, which Muslims worldwide pray towards each day.
They then head to Mina, the site of a giant tented city, before the hajj’s high-point: prayers on Mount Arafat, where the Prophet Mohammed is believed to have delivered his final sermon.
Before entering Mecca, pilgrims must first enter a state of purity, called ihram, which requires special dress and behaviour.
Men don a seamless shroud-like white garment that emphasises unity among believers, regardless of their social status or nationality.
Women, in turn, wear loose dresses, also white, exposing just their faces and hands.
Pilgrims arriving on buses were already trickling into Mina on Tuesday afternoon, greeted by staff offering them coffee and dates.
“I am so happy, it’s such an amazing feeling,” said Reem al-Shogre, a 35-year-old Saudi national performing hajj for the first time.
Hajj permits are allocated to countries on a quota basis and distributed to individuals by lottery. (AFP)